This invention relates generally to the art of surface coating, and more specifically to a method and apparatus for spray coating of surfaces with fine droplets of paints or the like produced by a rotating spray roll.
Heretofore, for coating the surfaces of structural parts and various other objects, spray guns have been used extensively for the relative ease of coating operation and the uniformity of the coatings obtained. The use of the spray guns is disadvantageous, however, in that they must be connected to a source of compressed air via pressure conduits which can greatly hamper their portability and hence the coating operation itself. Moreover, the paint or like coating agent sprayed by the spray guns are not necessarily neatly applied to the desired surfaces only, and the particles of the sprayed coating agent can further pollute the ambient air. This is highly objectionable from the viewpoint of hygiene for the workmen and of the economical use of the coating agent.
Other conventional coating methods involve the use of rollers, doctor blades or the like. While various surfaces can be coated neatly and with uniform thickness according to these known methods, they are quite ineffective to cause variations in the appearance, pattern or other properties of the coatings.